The National Toxicology Program (NTP) was established as a cooperative effort within the Public Health Service (PHS) of the Department of Health and Human Services (DHHS) to coordinate and manage toxicological research and testing activities within the Department, to provide scientific information on potentially hazardous chemicals to regulatory and research agencies, scientific and medical communities, and the public, and to strengthen the science base in toxicology. This interagency program comprises one of the world's largest scientific data resources for animal toxicity/carcinogenicity studies. The NTP consists of the relevant toxicological activities of the National Institute of Environmental Health Sciences, the National Institute for Occupational Safety and Health, the National Cancer Institute, and the National Center for Toxicological Research. Through its activities, the NTP provides either directly or indirectly, a large component of the basic scientific data that other Federal and State scientific and regulatory agencies as well as private sector organizations utilize in responding to issues relevant to the effects of chemicals on human health and the environment. Thus, the ultimate role of the NTP in the research and testing of chemicals and agents is the protection of health of the American public from exposure to hazardous chemicals.